A minority government is difficult to maintain so there's not likely to be any controversial legislation. At the same time none of the smaller parties wants another election too soon - they need to replenish their depleted coffers first. I give one about six months to a year.
Actually from what I know about Canadian electoral law the Governor General of Canada has say in whether an election is called or not in case of a no-confidence vote bringing down the minority government in power. He (or in Canada's case now, she) can ask the next party in line to try to form the government instead of calling another election.
I also heard that in the case of a minority government, the current prime minister has the option not to concede power and to try to form a government with other parties help. Unbelievably, this means that even if the Conservatives win more seats, Paul Martin has the option to keep power and try to form a government, an option he hasn't ruled out...